Claude Sonnet 5.5 vs GPT-5.3-Codex
| Signal | Claude Sonnet 5.5 | Delta | GPT-5.3-Codex |
|---|---|---|---|
Capabilities | 100 | -- | |
Pricing | 90 | +4 | |
Context window size | 95 | +6 | |
Recency | 100 | +14 | |
Output Capacity | 82 | -- | |
Benchmarks | 0 | -88 | |
| Overall Result | 3 wins | of 6 | 1 wins |
Score History
85.2
current score
GPT-5.3-Codex
right now
90.5
current score
Claude Sonnet 5.5
Anthropic
GPT-5.3-Codex
OpenAI
Claude Sonnet 5.5 saves you $175.00/month
That's $2100.00/year compared to GPT-5.3-Codex at your current usage level of 100K calls/month.
| Metric | Claude Sonnet 5.5 | GPT-5.3-Codex | Winner |
|---|---|---|---|
| Overall Score | 85 | 91 | GPT-5.3-Codex |
| Rank | #63 | #18 | GPT-5.3-Codex |
| Quality Rank | #63 | #18 | GPT-5.3-Codex |
| Adoption Rank | #63 | #18 | GPT-5.3-Codex |
| Parameters | -- | -- | -- |
| Context Window | 1000K | 400K | Claude Sonnet 5.5 |
| Pricing | $2.00/$10.00/M | $1.75/$14.00/M | -- |
| Signal Scores | |||
| Capabilities | 100 | 100 | Claude Sonnet 5.5 |
| Pricing | 90 | 86 | Claude Sonnet 5.5 |
| Context window size | 95 | 89 | Claude Sonnet 5.5 |
| Recency | 100 | 86 | Claude Sonnet 5.5 |
| Output Capacity | 82 | 82 | Claude Sonnet 5.5 |
| Benchmarks | -- | 88 | GPT-5.3-Codex |
Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.
Scores 85/100 (rank #63), placing it in the top 79% of all 290 models tracked.
Scores 91/100 (rank #18), placing it in the top 94% of all 290 models tracked.
GPT-5.3-Codex has a 5-point advantage, which typically translates to noticeably better performance on complex reasoning, code generation, and multi-step tasks.
Choose Claude Sonnet 5.5 when you need:
- Processing long documents or large codebases (1000K token context)
- Step-by-step reasoning and chain-of-thought problem solving
Choose GPT-5.3-Codex when you need:
- Step-by-step reasoning and chain-of-thought problem solving
Claude Sonnet 5.5 offers 24% better value per quality point. At 1M tokens/day, you'd spend $180.00/month with Claude Sonnet 5.5 vs $236.25/month with GPT-5.3-Codex - a $56.25 monthly difference.
Both models have comparable response speeds. For most applications, the latency difference is negligible.
When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.
Code generation & review
Based on overall model capabilities and architecture for coding tasks like generating functions, debugging, and refactoring
Customer support chatbot
Suitable for user-facing chat with competitive response times. Claude Sonnet 5.5 also offers lower per-token costs for high-volume support
Long document analysis
Larger context window (1000K tokens) can process longer documents, contracts, and research papers in a single pass
Batch data extraction
Lower output pricing ($10.00/M) reduces costs when processing thousands of records daily
Creative writing & content
Higher overall composite score (91/100) correlates with better nuance, coherence, and style in long-form content
Image understanding & OCR
Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly
GPT-5.3-Codex has a moderate advantage with a 5.299999999999997-point lead in composite score. It wins on more signal dimensions, but Claude Sonnet 5.5 has specific strengths that could make it the better choice for certain workflows.
By Use Case
Best for Quality
Claude Sonnet 5.5
Marginally better benchmark scores; both are excellent
Best for Cost
Claude Sonnet 5.5
24% lower pricing; better value at scale
Best for Reliability
Claude Sonnet 5.5
Higher uptime and faster response speeds
Best for Prototyping
Claude Sonnet 5.5
Stronger community support and better developer experience
Best for Production
Claude Sonnet 5.5
Wider enterprise adoption and proven at scale
by Anthropic
- Choose for Quality - Marginally better benchmark scores; both are excellent
- Choose for Cost - 24% lower pricing; better value at scale
- Choose for Reliability - Higher uptime and faster response speeds
- Choose for Prototyping - Stronger community support and better developer experience
- Choose for Production - Wider enterprise adoption and proven at scale
| Capability | Claude Sonnet 5.5 | GPT-5.3-Codex |
|---|---|---|
| Vision (Image Input) | ||
| Function Calling | ||
| Streaming | ||
| JSON Mode | ||
| Reasoning | ||
| Web Search | ||
| Image Output |
Claude Sonnet 5.5
Anthropic
GPT-5.3-Codex
OpenAI
Claude Sonnet 5.5 saves you $4.35/month
That's 22% cheaper than GPT-5.3-Codex at 1,000 tokens/request and 100 requests/day.
Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.
| Parameter | Claude Sonnet 5.5 | GPT-5.3-Codex |
|---|---|---|
| Context Window | 1M | 400K |
| Max Output Tokens | 128,000 | 128,000 |
| Open Source | No | No |
| Created | Sep 28, 2026 | Feb 24, 2026 |